Methods and systems for monitoring structures and systems

ABSTRACT

Methods and systems for structural and component health monitoring are provided. A system includes a plurality of sensor systems positioned about an object to be monitored and a processing system communicatively coupled to at least one of said plurality of sensor systems wherein the processing system includes an ontology and reasoning module configured to model the object to be monitored, reason about the received sensor data associated with the object to be monitored and reason about the relationships between the received sensor data to fuse the data into contextual information for the overall object to be monitored and a contextual analyzer configured to transmit the received sensor data to said ontology and reasoning module and to store the information into a contextual information database.

BACKGROUND OF THE INVENTION

This invention relates generally to structure and system healthmonitoring and more particularly, to methods and systems for monitoringstructure and system health using networked smart wireless sensordevices.

At least some known applications for wireless communication networksinclude industrial control and monitoring, intelligent agriculture,asset and inventory tracking, and security. Typical wireless sensingsystems comprise wireless sensors that passively gather large amounts ofdata from an environment, which is typically transmitted to a host nodefor evaluation by an individual specifically trained to manuallyevaluate the information as time permits. This typical sensor systemsometimes includes conversion of the signal from analog to digitaland/or signal conditioning. The raw time-series data is typicallytransmitted in its entirety to a host node where it is sometimes storedindefinitely and analyzed very infrequently.

A conventional system comprises a plurality of sensors coupled to aninterface which sends the information via a wired, large bandwidthtransmission to a computer at a remote location. Installation of thewires themselves are cost-prohibitive due to the distances over whichthe wires must pass, weight prohibitive due to the amount of the wiring,or infeasible in many other situations due to the environment where thesensor itself and respective wiring are located. Low-power wirelesstechnology has proved to be an enabler for wireless sensing in areasthat were previously unattainable, due to the ‘difficult-to-reach’ or‘difficult-to-wire’ nature of the installation or retrofit process.However, transmitting the raw data via a large bandwidth wireless systemmay consume significant amounts of power and create unnecessary networktraffic.

Preprocessing is sometimes used to reduce the amount of network trafficusing compression technology or by intelligently sending only the mostpertinent data. However, reducing the data available for analysis alsoreduces the effectiveness of the analysis.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a system for structural and component healthmonitoring includes a plurality of sensor systems positioned about anobject to be monitored and a processing system communicatively coupledto at least one of the plurality of sensor systems. The processingsystem includes an ontology and reasoning module configured to model theobject to be monitored, reason about the received sensor data associatedwith the object to be monitored and reason about the relationshipsbetween the received sensor data to fuse the data into contextualinformation for the overall object to be monitored. The processingsystem further includes a contextual analyzer configured to transmit thereceived sensor data to the ontology and reasoning module and to storethe information into a contextual information database.

In another embodiment, a method of monitoring the health of structuresand system components includes positioning a plurality of sensor systemsproximate an object to be monitored wherein the sensor systems eachinclude one or more sensors configured to detect object data that isrelated to the object health. The method also includes wirelesslytransmitting the data to at least one of another one of the plurality ofsensor systems and a processing system, and analyzing the data todetermine a contextual relationship between each of the plurality ofsensor systems and the received data such that a present state of theobject is determined.

In yet another embodiment, a sensor networking system for monitoring thehealth of an aircraft structure and system components related to theaircraft includes a plurality of sensor systems positioned about theaircraft. The sensor systems include a flexible substrate, an energyharvesting system, a rechargeable battery, and a microprocessor thatcontrols wireless communication between at least one of the sensorsystems and a processing system remote from the plurality of sensorsystems, the plurality of sensor systems further including sensorsincluding a plurality of different modalities. The system also includesa processing system communicatively coupled to at least one of theplurality of sensor systems, the processing system configured to receiveat least one of sensor data and fused sensor data the processing systemincluding a situation awareness analyzer configured to determine anoverall present state of the aircraft by observing the events andactivities within the aircraft structure and aircraft systems andcorrelating individual data elements and behavioral models to deduceoverall system state and behavior.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic block diagram of a Structure and Systems HealthMonitoring System (SSHMS) in accordance with an exemplary embodiment ofthe present invention;

FIG. 2 is a plan view of an aircraft including a Structure and SystemsHealth Monitoring System (SSHMS) in accordance with an exemplaryembodiment of the present invention;

FIG. 3 is a cross-sectional view of a portion of a fuselage of theaircraft shown in FIG. 2; and

FIG. 4 is a flow diagram of an exemplary information generation flow forStructure and Systems Health Monitoring System (SSHMS) shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is schematic block diagram of a Structure and Systems HealthMonitoring System (SSHMS) 100 in accordance with an exemplary embodimentof the present invention. In the exemplary embodiment, SSHMS 100includes at least one sensor system 102 and at least one onboardprocessing system 104. Sensor system 102 may include a variety of sensorsystem types. For example, a single sensor system 106 may include only asingle sensor and may not include an onboard storage memory capability.A memory sensor system 108 may include a single sensor and an onboardstorage memory for relatively long term storage of data. A multi-sensorsystem 110 may include a plurality of sensors and may include an onboardstorage memory for relatively long term storage of data.

In the exemplary embodiment, sensor systems 102 generally include asensor 112, a sensor access module 114, and a sensor access agent anddata processor 116. Sensor systems 108 and 110 also include an onboardmemory 118 for storing raw or processed data, swappable programinstruction code, and look-up tables (LUT), as needed to perform thevarious functions of sensor systems 102. Sensor systems 102 includerelatively thin lightweight energy harvesting materials 120 connected towafer thin polymer based or lithium ion rechargeable batteries 122 topower embedded microprocessors. In addition, these individualmicroprocessors 116 and integrated micro-sensors 112 are attached to athin planar antenna 124.

Sensor systems 102 include small lightweight sensors 112 with embeddedlocal micro-processing for collecting, deciphering and recording dataalong with wireless communication capability. Sensor systems 102 providespecific environmental and performance data for the components,structure, and systems that encompass an entire vehicle wide componentset. Such data, when integrated, permits a detailed understanding of therelationship between the performance and environment of each component,and how that relationship impacts the overall health of the set ofcomponents that make up the entire airplane. Sensor systems 102 includea flexible substrate 103 that is backed by a self-adhesive layer forattachment to a component or structure of interest.

Sensor systems 102, which combine energy harvesting and storage andmicro-processing record information such as but not limited to impact,thermal conditions, corrosion, moisture, electrical parameters, load,dynamic cycles, and combinations including any of the above, directly tothe data processors 116 as generated by the integrated micro-sensors112. Data processors 116 include on-chip memory for storing the sensordata and control features that control wireless communication betweensensor systems 102 and/or onboard processing system 104. In theexemplary embodiment, sensor systems 102 are mounted on appliqué forease of application and removal for the structural applications and areintegrated into the name plate for the individual systems basedcomponents.

Sensor access module 114 provides wrapper functions for underliningsensor 112. The wrapper function provides a consistent interface, forexample, but is not limited to an Application Programming Interface(API), to the upper layers of sensor access agent and data processor116, to control and retrieve data from sensor 112. The sensor accessagent and data processor 116 is the service entity supporting retrievalof sensor data via a set of pre-defined common interfaces that onboardprocessing system 104 can invoke. The data processor performs the firsttier data fusion of raw sensor data into a preliminary form ofcontextual information. The degree of data fusion performed by the dataprocessor depends on the type of sensor and the complexity of the sensorsystem. For example, data processors in sensor system 110 support thefusion of data retrieved from a first sensor subsystem 128 and a secondsensor subsystem 130 into a coherent form and representing theinformation in a form that is relevant to sensor system 110 context atthe time the data is sensed. This information, along with the raw sensordata, is stored within local storage device 118. The stored informationcan be retrieved by onboard processing system 104 at a later time fordecision support system application or as a log history to monitor thebehavior of sensor system 110.

Onboard processing system 104 may receive sensor data for variousstructural and system components and combine different types of sensordata (regardless of the source and regardless of the component or eventbeing monitored) to generate a more accurate assessment of thestructural and system health of the specified component.

Onboard processing system 104 is configured to process the sensor dataalong with any historical data and pre-defined contextual information todetermine or generate a contextual assessment of the condition and/orstatus of the structure and system. Onboard processing system 104receives sensor data from one or more structural or system componentsand combines this data, potentially from different sensor types, to makea more complete condition estimate for the specified component and/orthe system as a whole. Onboard processing system 104 may processhistorical data for trending purposes.

Onboard processing system 104 may also receive any amount of manualinspection data or manual inspection data may be processed afterdownload of the onboard processing system 104 data to a central server.As used herein, “manual inspection data” is data that has been collectedwith human labor, as opposed to data that has been collected via anautomated system. Although one preferred embodiment of Structure andSystems Health Monitoring System (SSHMS) 100 eliminates the need formanual inspection data, Structure and Systems Health Monitoring System(SSHMS) 100 is capable of processing such data if it is available.Structure and Systems Health Monitoring System (SSHMS) 100 is capable ofmerging manual inspection data with automated sensor data.

Onboard processing system 104 is configured to perform any number ofsuitable data fusion techniques during the processing of the sensor dataand optional manual inspection data. Onboard processing system 104processes its input data in an intelligent manner to generate a morecomplete, and generally more reliable and accurate assessment of thestructural health of the monitored component. Onboard processing system104 utilizes techniques including but not limited to, expert systems,neural networks, and artificial intelligence technologies. Onboardprocessing system 104 is also configured to perform data trending tofilter noise from the sensor data and to otherwise enhance the accuracyof the health assessment. For example, onboard processing system 104performs time domain and spatial filtering of the sensor data. Datatrending functionality includes but is not limited to smoothing, forexample, providing an accurate estimate of the past history of thesensor data assessment, filtering, for example, computing an accuratenoise rejecting estimate of the current structural and systems healthstate taking into account past history data, and/or prediction, forexample, projecting the sensor data evolution into the future.

The data is recorded on the microprocessor and then intermittentlyrelayed to an onboard processing system 104 by an embedded rule-basedagent. The migration of the data from data processors 116 to theindividual onboard processing systems 104 populated across the entirecritical component family of the airplane, both structural and systems,including propulsion, provides the smart characteristics of memory, datamanipulation, and wireless communication, to SSHMS 100. Onboardprocessing system 104 includes a small externally or internally mountedtransmit/receive antenna 126 depending on the location of the sensorsystems 102. In the exemplary embodiment, antenna 126 utilizes UHF orSHF band frequencies. Antenna 126 sends out a signal to the varioussensor systems 102 currently of interest. The identified sensor system102 energizes its wireless communication circuit and transmits theinformation of interest via energy emitted by the attached thin planarantenna 124 using power from the integrated thin integrated rechargeablebattery 122. Sensor systems 102 are intermittently interrogated todownload the sensor data to the on-board repository.

Onboard processing system 104 monitors, records, and appropriatelygenerates notification alerts with accurate information on a real timebasis. In the exemplary embodiment, onboard processing system 104includes seven major components and is designed to function remotelyfrom sensor system 102. In the exemplary embodiment, onboard processingsystem 104 executes on an independent computing system. In analternative embodiment, onboard processing system 104 is collocated withanother on-board computing system. Sensor controller 132 permits a dataacquisition module 134 to retrieve real time and historical sensor dataand contextual information 135 from sensor system 102. The real timesensor data interrogation involves the establishment of either asynchronous TCP socket connection from sensor controller 132 to thesensor access agent 116, or an asynchronous TCP socket connection fromthe sensor access agent to sensor controller 132. In addition, sensorcontroller 132 can also retrieve historical sensor data and sensorcontextual-information from the sensor's local-store 118.

Selection of the specific sensor system 102 to be interrogated, orretrieval of historical data, and the interrogation periodicity arecontrolled by a situation awareness analyzer 136. Once the data isreceived, data acquisition module 134 publishes or transmits thereceived data/information to a contextual analyzer 138 and situationawareness analyzer 136. Contextual analyzer 138 uses the data as aninput object for an ontology and reasoning module 140 to fuse the datainto contextual information for the overall airplane system andsubsequently store the information into the contextual informationdatabase 135. Ontology and reasoning module 140 includes an ontologyengine 142, which comprises a data model representing a domain such asthe entire aircraft or a smaller defined portion of the aircraft and isused to reason about the objects in that domain and theirinter-relationships. The objects may be defined as for example, but notlimited to components, systems or structures that make up the aircraftor the aircraft environment. A reasoning module 144, which is thereasoning rule engine, is used to reason the relationships.

An array sensing algorithm module 146 includes logic that governs theorder in which specific sensor systems 102 are interrogated and theperiodicity of their respective interrogations. This logic is fed intothe situation awareness analyzer 136 in order to direct sensorcontroller 132. In addition to the logic from array sensing algorithmmodule 146, situation awareness analyzer 136 also uses discovery module148 to determine which sensor systems 102 to interrogate. In theexemplary embodiment, discovery module 148 includes three stages, a nodediscovery 150, which determines the presence of a node for example,sensor system 102, a service discovery 152, which discovers the serviceprovided by the given node, and a contextual information discovery 154,which discovers information relevant to the current context.

Situation awareness analyzer 136 provides a single picture of thepresent state of the airplane system so that it can monitor, record, andappropriately generate notification alerts with the proper informationin real time. In order to accomplish this and compile an overall view ofthe current state, situation awareness analyzer 136 needs to be aware ofthe current and past contextual information generated by the contextualanalyzer 138, discovery information from the discovery module 148, logicfrom the array sensing algorithm module 146, data reported by the dataacquisition module 134, and retrieve required sensor data to furtheraugment the overall view.

This architecture creates a record of the environment and theperformance of each of the critical components of the airplane duringflight. These records would be used to construct correlations betweenthe interaction between the flight-environment/structural-performanceand the subsequent systems performance. In addition, the reciprocal ofthis would also be utilized, where the system performance impacts theflight characteristics and structural behavior of the airplane. Fromthis integrated data set, algorithms are dynamically adjusted and/or newalgorithms constructed that provide input to design improvements, flightconditions to avoid and the construction of detailed and customizedmaintenance activities for individual airplanes based not only on thefamily of individual parts installed but also on the anticipated use ofthe airplanes.

Integrated vehicle health monitoring using Structure and Systems HealthMonitoring System (SSHMS) 100 includes a large number of distributedsensor systems 102 communicatively coupled into a network or a pluralityof interconnected networks. Such a sensor network improves thesituational awareness of the vehicle state that includes its system andsub-system assemblies over the duration of product life. However, thelarge number of sensors within the vehicle requires data from thesedisparate and heterogeneous sensors to be processed and combinedintelligently to determine a clear and unambiguous view of the vehiclestate that is temporally relevant for maintenance and planning decisionsupport systems. Data from the individual sensor systems 102 isintelligently analyzed to extract information and the information frommultiple sensor systems 102 utilizing sensors 112 of differentmodalities is intelligently combined to create a fused situationalawareness view of the overall vehicle state. Intelligent information isextracted from sensor data and fused from multiple modalities to providean overall view of the vehicle system and sub-system states. Events andactivities within systems and sub-systems are observed and individualdata elements and behavioral models are correlated to deduce overallsystem state and behavior. The correlation of individual data elementsand behavioral models within temporal space also enables estimating thestates of the system and sub-systems for pro-active decision supportsystems. The estimated state can include any future anticipated statewhich may be caused by events and activities that have happened in therelated environment. The sensor networks are arranged for distributedmonitoring with low-power devices and ad hoc wireless networkingcapability to inter communicate with onboard processing system 104.Sensor systems 102 include adaptive storage functions by appropriatelyfusing the sensed data to ensure that it can effectively be communicatedto onboard processing system 104. Data reduction at the sensor sourceminimizes the communication requirements thereby easing the powerrequirements of the overall system since computation is more powerefficient when compared to communication. Structure and Systems HealthMonitoring System (SSHMS) 100 optimizes a balance between localcomputation versus communication while ensuring the required informationquality is retained to enable onboard processing system 104 to functioneffectively regardless of data fusion at the sensor sources or atintermediary aggregation points. Array sensing algorithms 146 andsensors 112 that incorporate directional sensing capabilities provide amore complete view of the system and sub-systems in particular areas.Local reasoning is incorporated into the sensor source to enable timeand space based analysis to measure the sensor viewpoint for the event.The sensor sources include power-aware computation to minimize thevolume of data stored onboard the sensor device and communicated toonboard processing system 104.

FIG. 2 is a plan view of an aircraft 200 including a Structure andSystems Health Monitoring System (SSHMS) 100 in accordance with anexemplary embodiment of the present invention. Aircraft 200 comprisesgenerally a framework structure covered by an aerodynamic skin. Duringvarious flight operations, the structure and skin are subject tocompressive, bending, torsional, and tensile static or fatigue loads dueto propulsive and drag forces and thermo-dynamic expansion andcontraction of the components of the structure and the skin. Such loadsover time may weaken or damage the stressed components and structures.Periodic inspections are relied on to discover the precursors of failureso that maintenance may correct problems prior to a catastrophic failurethat damages aircraft 200 or impacts scheduling aircraft 200 for normalflight duty.

Structure and Systems Health Monitoring System (SSHMS) 100 includes aplurality of sensor systems 102 applied to structural members and skinsections of aircraft 200. A reader 202 including a transmit/receiveantenna 204 is positioned to transmit an interrogation signal to one ormore of sensor systems 102. Each sensor system 102 responds to theinterrogation signal with the information requested by reader 202.Reader 202 may request raw data or data that has been primarilyprocessed by sensor system 102, or may request stored data stored instorage device 118. In the exemplary embodiment, reader 202 comprises anonboard processing system 104 described above. In an alternativeembodiment, reader 202 comprises a relay device configured to receivedata from one or more sensor systems 102 and relay the data to anonboard processing system 104 positioned remotely on aircraft 200. Inthe exemplary embodiment only one reader 202 is shown, howeveradditional readers 202 and/or onboard processing systems 104 may beincluded in Structure and Systems Health Monitoring System (SSHMS) 100.In the exemplary embodiment, sensor systems 102 are selected and placedto monitor structural characteristics of the operation of aircraft 200.Such sensor systems 102 may include vibration sensors, strain sensors,temperature sensor, and other sensors configured to sense conditionsassociated with the operation of aircraft 200.

FIG. 3 is a cross-sectional view of a portion of a fuselage 300 ofaircraft 200 (shown in FIG. 2). In the exemplary embodiment, fuselage300 includes a passenger floor 302 dividing fuselage 300 into an upperpassenger 304 compartment and a lower cargo compartment 306. A reader308 is positioned such that wireless communication signals transmittedfrom reader 308 are capable of being received by a plurality of sensorsystems 102. Sensor systems 102 are positioned on for example, but notlimited to passenger compartment equipment, passenger carry-on stowagebins, in the vicinity of passenger seating, and system components andcargo in lower cargo compartment 306. Sensor systems 102 are configuredto monitor systems and components within range of reader 308. In atleast some embodiments, sensor systems 102 include sensors 112 that areselected with properties capable of detecting an/or measuring passengeractivity and chemical, biological, and radioactive agents that may becarried or otherwise transported into passenger compartment 304.

FIG. 4 is a flow diagram 400 of an exemplary information generation flowfor Structure and Systems Health Monitoring System (SSHMS) 100 (shown inFIG. 1). Structural sensor systems 402 include integrated energyharvesting, thin lightweight rechargeable battery, thin lightweightantennas, integrated microprocessor and various miniaturized integratedsensors mounted on a flexible substrate formed in some embodiments intoan appliqué having a self-adhesive backing. Energy may be harvested fromelectromagnetic radiation received from for example, a reader onboardprocessing system 104, a piezo device using vibrations inherent in themounted location, or converting thermo energy into electrical energyonboard the sensor system.

Systems/components sensor systems 404 include integrated energyharvesting, thin lightweight rechargeable battery, thin lightweightantennas, integrated microprocessor and various miniaturized integratedsensors. Information stored on board the microprocessors is periodicallytransmitted 406 wirelessly to communication devices that store the dataand further transmits the data to a database for analysis usingcorrelation algorithms. Information is provided 408 to the designcommunity for detailed data on the environment and loads placed and theproducts subsequent performance on the structures and systems of theairplane. Information from the integrated sensors is used 410 to buildand fuel algorithms to provide customized maintenance activities basedon more accurate predictive estimates enabled by this richer data set.Improved 412 overall airplane reliability and lower cost designs resultfrom awareness of the contextual relationships of the events andactivities occurring with the structure and system components, whichalso provides more accurate predictive capability 414 to enable leanmaintenance planning and improved flight safety.

The above-described methods and systems for monitoring aircraftstructures and system components are cost-effective and highly reliable.The methods described herein utilize small lightweight sensors withembedded local micro-processing for collecting, deciphering andrecording data along with wireless communication capability. Suchwireless-enabled/smart-sensors/identifiers permit acquiring specificenvironmental and performance data for the components that encompass theentire aircraft wide component set. This data is then integrated todetermine a detailed understanding of how the performance andenvironment of each of the components impacts the overall health of theset of components that make up the entire airplane.

While the invention has been described in terms of various specificembodiments, those skilled in the art will recognize that the inventioncan be practiced with modification within the spirit and scope of theclaims.

1. A structural and component health monitoring system comprising: aplurality of sensor systems positioned about an object to be monitored;a processing system communicatively coupled to at least one of saidplurality of sensor systems, said processing system comprises: anontology and reasoning module configured to model the object to bemonitored, reason about the received sensor data associated with theobject to be monitored and reason about the relationships between thereceived sensor data to fuse the data into contextual information forthe overall object to be monitored; and a contextual analyzer configuredto transmit the received sensor data to said ontology and reasoningmodule and to store the information into a contextual informationdatabase.
 2. The system in accordance with claim 1 further comprising adata acquisition module and sensor controller that permits said dataacquisition module to retrieve real time and historical sensor data andcontextual information from said sensor system.
 3. The system inaccordance with claim 1 further comprising a discovery module comprisingat least one of a node discovery, a service discovery, and contextualinformation discovery wherein said node discovery is configured todetermine a presence of a node, wherein said service discovery isconfigured to determine a service provided by the determined node, andwherein said contextual information discovery is configured to determineinformation relevant to the current context.
 4. The system in accordancewith claim 1 further comprising a contextual information databaseconfigured store sensor data fused by said ontology and reasoning moduleinto contextual information for the overall object to be monitored. 5.The system in accordance with claim 1 further comprising an arraysensing algorithm module comprising logic that governs at least one ofthe order in which specific sensor systems are interrogated and theperiodicity of their respective interrogations.
 6. The system inaccordance with claim 1 further comprising a situation awarenessanalyzer configured to determine a present state of the object to bemonitored, generate notification alerts in real time, and receivecurrent and past contextual information generated by a contextualanalyzer.
 7. The system in accordance with claim 1 further comprising asituation awareness analyzer configured to receive discovery informationfrom a discovery module, logic from the array sensing algorithm module,sensor data reported by a data acquisition module, and direct a sensorcontroller to interrogate a sensor system.
 8. The system in accordancewith claim 1 wherein said plurality of sensor systems comprises an adhoc network configured to communicate sensor data between the pluralityof sensor systems and an onboard processing system.
 9. The system inaccordance with claim 1 wherein at least one of said plurality of sensorsystems comprises a flexible substrate.
 10. The system in accordancewith claim 1 wherein at least one of said plurality of sensor systemscomprises an energy harvesting system.
 11. The system in accordance withclaim 1 wherein at least one of said plurality of sensor systemscomprises a flexible film rechargeable battery.
 12. The system inaccordance with claim 1 wherein at least one of said plurality of sensorsystems comprises a microprocessor that controls wireless communicationbetween at least one of said sensor systems and an onboard processingsystem.
 13. A method of monitoring the health of structures and systemcomponents, said method comprising: positioning a plurality of sensorsystems proximate an object to be monitored, said sensor systems eachincluding one or more sensors configured to detect object data that isrelated to the object health; wirelessly transmitting the data to atleast one of another one of the plurality of sensor systems and aprocessing system; and analyzing the data to determine a contextualrelationship between each of the plurality of sensor systems and thereceived data such that a present state of the object is determined. 14.The method in accordance with claim 13 further comprising: fusing dataretrieved from a first sensor subsystem and a second sensor subsysteminto a contextual form based on the sensor data type and sensor systemlocation relative to the object and the others of the plurality ofsensor systems at the time the data is sensed; and storing the fuseddata and the raw sensor data within a local storage device onboard saidsensor system.
 15. The method in accordance with claim 13 furthercomprising transmitting fused data and raw sensor data from the sensorsystem to the processing system in response to a command from theprocessing system.
 16. A sensor networking system for monitoring thehealth of an aircraft structure and system components related to theaircraft, said system comprising: a plurality of sensor systemspositioned about the aircraft, said sensor systems comprise a flexiblesubstrate, an energy harvesting system, a rechargeable battery, and amicroprocessor that controls wireless communication between at least oneof said sensor systems and a processing system remote from saidplurality of sensor systems, said plurality of sensor systems furthercomprising sensors including a plurality of different modalities; and aprocessing system communicatively coupled to at least one of saidplurality of sensor systems, said processing system configured toreceive at least one of sensor data and fused sensor data, saidprocessing system comprising a situation awareness analyzer configuredto determine an overall present state of the aircraft by observing theevents and activities within the aircraft structure and aircraft systemsusing the plurality of sensor systems and correlating individual dataelements and behavioral models to deduce overall system state andbehavior.
 17. The system in accordance with claim 16 wherein saidsituation awareness analyzer is further configured to generatenotification alerts in real time, and receive current and pastcontextual information generated by a contextual analyzer.
 18. Thesystem in accordance with claim 16 wherein said situation awarenessanalyzer is further configured to receive discovery information from adiscovery module, logic from the array sensing algorithm module, sensordata reported by a data acquisition module, and direct a sensorcontroller to interrogate a sensor system.
 19. The system in accordancewith claim 16 further comprising an ontology and reasoning moduleconfigured to model the aircraft structure and system components relatedto the aircraft, reason about the received sensor data associated withthe aircraft structure and system components related to the aircraft andreason about the relationships between the received sensor data to fusethe data into contextual information for the overall aircraft structureand system components related to the aircraft.
 20. The system inaccordance with claim 16 further comprising a contextual analyzerconfigured to transmit the received sensor data to an ontology andreasoning module and to store the information into a contextualinformation database.
 21. The system in accordance with claim 16 furthercomprising a data acquisition module and sensor controller that permitssaid data acquisition module to retrieve real time and historical sensordata and contextual information from said plurality of sensor systems.22. The system in accordance with claim 16 further comprising adiscovery module comprising at least one of a node discovery, a servicediscovery, and contextual information discovery wherein said nodediscovery is configured to determine a presence of a node, wherein saidservice discovery is configured to determine a service provided by thedetermined node, and wherein said contextual information discovery isconfigured to determine information relevant to the current context. 23.The system in accordance with claim 16 further comprising a contextualinformation database configured store sensor data fused by said ontologyand reasoning module into contextual information for the overallaircraft structure and system components related to the aircraft. 24.The system in accordance with claim 16 further comprising an arraysensing algorithm module comprising logic that governs at least one ofthe order in which specific sensor systems are interrogated and theperiodicity of their respective interrogations.
 25. The system inaccordance with claim 16 wherein said plurality of sensor systemscomprises an ad hoc network configured to communicate sensor databetween the plurality of sensor systems and an onboard processingsystem.